This invention generally relates to a balloon catheter system and method for dilating a prostatic urethra.
Dilatation of the prostatic urethra to eliminate or minimize urethral blockage has been considered for many years. For example, Guthry in 1830, Civale in 1841, Mercier in 1850 and Kramer in 1910 all developed metal dilators to unblock urethral obstructions. A good description of the early work in this area can be found in Hinman, F., Jr. (Ed.) Benign Prostatic Hypertrophy, Chapter 5, Springer-Valag, 1983. Russinovich et al. utilized a balloon dilatation catheter which was developed for angioplasty by Gruntzig et al. in the late 1970s to successfully dilate the prostatic urethra of several male patients which has been partially occluded (Urologic-Radiology, 2, 33-37, 1980).
Balloon catheters for dilating occluded prostatic urethras are commercially available. They are very similar to the dilatation catheters utilized for valvuloplasty procedures, except that the catheter shafts are much shorter.
In typical prostatic dilatation procedures, a guiding catheter is first introduced through the patient's urethra into the bladder so that retrograde urethrography can be performed to outline the external sphincter and then a flexible guidewire is advanced through the guiding catheter into the patient's bladder. The balloon dilatation catheter is advanced over the guidewire until the balloon thereof is located within the patient's prostatic urethra where it would be inflated to an elevated pressure, usually above 2 atmospheres, to dilate the prostatic urethra and the surrounding prostate gland. A cystoscope is employed in this procedure to observe the placement of the dilatation catheter and the dilatation procedures as well as to examine of the urethra both before and after the procedure.
The dilatation catheters presently employed for prostatic dilatations generally have relatively large profiles which makes advancement and accurate placement thereof very difficult. Commercially available catheters have much too large a profile to be advanced through the lumen or working channel of a cystoscope particularly a flexible cystoscope which has a very small working channel.
What has been needed and heretofore unavailable is a dilatation catheter which is suitable for prostatic dilatations but which has a sufficiently low profile to pass through the working channel or lumen of a cystoscope. The present invention satisfies that need.